FMIC? Are you sure???

[Miguel]

am i right in thinking the colder the air the more volume you can pump into the engine in the same area of pipe?

for example if you put an inflated baloon in liquid nitrogen it will shrink, but then when it warms up it inflates again, the volume of air doesn't change, it just becomes more compact and need less area to exist.

so in theory you could get more air into the engine if its colder?

 

feel free to shoot me down

 

Correct:)

[Guest gzaerojon]

Correct:)

 

 

thankyou sir

[b_have]

He's either taking the piss or on the piss. Most likely both.

 

Something related to the search button? I'll get my coat.

[carl0s]

am i right in thinking the colder the air the more volume you can pump into the engine in the same area of pipe?

for example if you put an inflated baloon in liquid nitrogen it will shrink, but then when it warms up it inflates again, the volume of air doesn't change, it just becomes more compact and need less area to exist.

so in theory you could get more air into the engine if its colder?

 

feel free to shoot me down

 

Well, yeah. I don't think it's a case of "you can pump more in", more a matter of fact that more air (molecules) do get in there, because as you say the air is denser.

[Guest gzaerojon]

Well, yeah. I don't think it's a case of "you can pump more in", more a matter of fact that more air (molecules) do get in there, because as you say the air is denser.

 

 

thats what i meant, couldn't think of a better term

[Miguel]

Something related to the search button? I'll get my coat.

 

Yeah it just hit me Call me bullet, I'm defo getting slower.

[carl0s]

So I suppose the point to consider is that 20psi from small turbos is not the same as 20psi from large turbos. The thing to consider regarding cooling capacity would be CFM or air volume or something.

 

Actually.. I am now re-confused. The big turbos are blowing their air into the same engine as the large turbos, so the mac donalds straw and drainpipe analogy doesn't suit does it? Where does the pressure get measured?

 

I know we can say that pressure can vary regardless of actual volume of air, but once that volume of air tries to get pushed through (into) the same orifice, surely then the pressure can then be taken as a comparative measurement of actual amount?

 

ok. I'm definately re-confused

[carl0s]

Any good books to recommend?

[Miguel]

Don't forget its not a closed circuit. The engine is digesting what it is fed ( to a point). A larger turbo can move more volume of air to the engine at the same pressures. As you say the pipes are the same size so if you welded up the end of the IC so it now became a compressor bottle a large turbo would fill that quicker and achive said pressure faster than a smaller one because it moves more volume of air . But because the engine is digesting what is fed to it the flow of air that is passing through them pipes would be greater on a larger turbo at said pressure hence the engine puts out more power on the larger turbo as it is having to eat it burn it and poo it faster.

 

So back on target, Would an SMIC haddle the larger volumes of air passing through it from a larger framed turbo at said boost? although this is based upon what turbo is being spoke about here.

[Jake]

I am now re-confused. The big turbos are blowing their air into the same engine as the large turbos, so the mac donalds straw and drainpipe analogy doesn't suit does it?

I bloody said that in post 13 !!!!1

[carl0s]

I think I might have sussed it - working on the assumption that pressure is measured at the manifold... When the big turbo is creating 20psi of air, the engine can eat up this air very quickly. The big turbo can give more and more and more air (loads of volume), while the engine eats up more and more, based on volume, and still maintain 20psi of air pressure waiting to get into the cylinders.

 

The small turbos can maintain that same 20psi of air, but only because the engine isn't eating much of their air because it knows they aren't able to provide it (volume).

 

So the mac donalds straw and drainpipe analogy does make sense based on the fact that the engine can vary the amount of air it uses up.. it's orifice size if you like.

 

Does this make any sense Migster? .. 'til tomorrow, I'm off to bed.

[carl0s]

Don't forget its not a closed circuit. The engine is digesting what it is fed ( to a point). A larger turbo can move more volume of air to the engine at the same pressures. As you say the pipes are the same size so if you welded up the end of the IC so it now became a compressor bottle a large turbo would fill that quicker and achive said pressure faster than a smaller one because it moves more volume of air . But because the engine is digesting what is fed to it the flow of air that is passing through them pipes would be greater on a larger turbo at said pressure hence the engine puts out more power on the larger turbo as it is having to eat it burn it and poo it faster.

 

So back on target, Would an SMIC haddle the larger volumes of air passing through it from a larger framed turbo at said boost? although this is based upon what turbo is being spoke about here.

 

Yay. Haven't read every word yet, got the gf bitching at me to come back to bed, but i think i got it

[Miguel]

I think I might have sussed it - working on the assumption that pressure is measured at the manifold... When the big turbo is creating 20psi of air, the engine can eat up this air very quickly. The big turbo can give more and more and more air (loads of volume), while the engine eats up more and more, based on volume, and still maintain 20psi of air pressure waiting to get into the cylinders.

 

Yip yip yip

[RedM]

How much more or less efficient is an unducted FMIC compared to the fully ducted SMIC?

 

Seems to me that an unducted FMIC is a bit like going fishing with a trawler net.

 

Thoughts?

[Dragonball]

 

So back on target, Would an SMIC haddle the larger volumes of air passing through it from a larger framed turbo at said boost? although this is based upon what turbo is being spoke about here.

 

Mig - would the pipe size be the deciding factor here too?

 

No matter how 'efficient' the SMIC (or FMIC) the potential weakest link will be the pipe sizing to allow said volume through too...?

[Spyda]

P*V = nRT

 

P is Pressure

V is Volume

n is the number of moles of the gas

R is the Universal Gas constant ( approx 8.3 J/mol*K)

T is Temperature measured in Kelvins

 

I'll let you lot do the maths....

[Dragonball]

P*V = nRT

 

 

n is the number of moles of the gas

quote]

 

They are blind to this science

 

 

Sorry...

[Guest Usmann A]

Havent read all the thread. But I would say you would be having lots of compressor surge.

 

small cooler, displaces less volume, the mass flow rate through it will not be the same, as a bigger one ovbiously. So thus causing a restriction, and the turbo is making more air than the motor can ingest. Thus why we have anti-surge valves, but if i was surgeing on a 74, and youve gone bigger than that on a SMIC, youll decresce turbo life.

 

I ran a ARC thin cooler, Marco has it now, it was causing me to have lots of surgeing pre 4000rpm, due to it size and flowrate.

 

Now, I have a 4ROW, and much bigger pipeing, i reacon I could drop to a .68 on that 74 and still not surge, LOL.

 

Just my 02 rupees,

[michel lane]

have you seen the stock smic ?? its pressed togeather not welded !!!... in the early years when i upgraded to my T78 and ran the SMIC , it lasted 3 weeks at 18psi , you have to remember , psi is different from flow rate , you can be running 18psi on a sp61 but produce twice the flow rate as stock twins but run the same psi . Well i had an AEM and running the smic i measured the charge temp going into the TB , then when i put the FMIC on it , the charge temp dropped by 20 degrees, thats a bid difference !!!. I would imagine if you had a chris wilson smic or the greddy 4 row smic , it would be fine , as they are welded together , but a stock smic !!! no i would risk it , even if it held together iam sure there will be leaks in the system .

 

I believe the greddy smic , which is a chopped version of the 4 row , is measured to 700hp.

 

then again what do i know

[Guest Usmann A]

You have to remeber that when copmressed air is being cooled down, the moleclues space themselves more from each other(returning to normal congiuration for atmosph.), now the bigger the volume they have to lose thier heat,the more they spread themselves, the more cooler the chrage becomes, ovb with intercooler they have designed turbulators to try and balance the cooling vs pressure.

 

Give something hot more space (volume) and more surface area(fins,turbulators, etc) the greater the heat loss.

 

I see what you mean tho Tony, I havent expericned a SMIC on a single myself, but have on a small cooler, and that didnt give me great charge temps either, not to mention Surgeing.

 

thats my take on it,

 

edited, lets all jump Tony!! haahah

[michael]

The ARC SMIC I had a while ago was a lovely piece of work, apparently capable of some good numbers and very efficient - sadly I didn't get chance to try it thanks to a rogue Corsa trying to see how strong it was

[Guest Usmann A]

Agreed, ARC make some lovely stuff, to be fair chrage temps werent that bad, could have been better, the fact that it couldnt flow for it was what made me change.

[chilli]

hmmm I think TLicense has a valid point.

 

Larger turbos work within the efficiency band and thus produce cooler air. This means you can get more air in at the same pressure, however this does not affect the same basic question that if it has been pre-heated less due to turbo working more efficiently, why then is it essential to slam a much larger FMIC on? If anything the SMIC would now be almost over specified if the turbos were also so uprated that they worked very efficiently?

[Spyda]

hmmm I think TLicense has a valid point.

 

Larger turbos work within the efficiency band and thus produce cooler air. This means you can get more air in at the same pressure, however this does not affect the same basic question that if it has been pre-heated less due to turbo working more efficiently, why then is it essential to slam a much larger FMIC on? If anything the SMIC would now be almost over specified if the turbos were also so uprated that they worked very efficiently?

 

No

 

This is what use those useles Science lessons were.

[chilli]

ok so which bit of the science is wrong then...